2&#39;,5&#39;-dihalo-3-tert.alkyl-5-nitrosalicylanilides for combatting lepidoptera chewing larvae

ABSTRACT

Compounds having a 2&#39;&#39;, 5&#39;&#39;-dihalo-3-tert.alkyl-5nitrosalicylanilido nucleus useful in combatting chewing insect larvae species of the order Lepidoptera, particularly species of the family Noctuidae.

United States Patent [191 Darlington et al.

11] 3,721,737 ]March 20, 1973 [54] 2 ,5 '-DIHALO-3-TERT.ALKYL-5-NITROSALICYLANILIDES FOR COMBATTING LEPIDOPTERA CHEWING LARVAE [75]Inventors: Walter A Darlington, St. Louis;

John P. Chupp, Kirkwood, both of Mo.

[73] v Assignee: Monsanto Company, St. Louis, Mo, [22] Filed: Nov. 15,1968 211 App]. No.: 776,276

3,134,71 l 5/1964 Reller et.al ..424/233 3,278,372 10/1966 Taborsky..424/230 3,309,267 3/1967 Starkey 424/23O 3,332,996 7/1967 Zerweck etal. 424/233 X 3,382,145 5/1968 Chupp et a1 ..424/23O 3,388,163 6/1968Early et a1. .....424/230 X 3,466,370 9/1969 Broome et al. ..424/233OTHER PUBLICATIONS Chemical Abstraacts Vol. 60; 10938c, 1960.

Primary Examiner-Jerome D. Goldberg Assistant Examiner-Leonard SchenkmanAttorney-Neal E. Willis, John J. Henschke, Jr., A1- bert J. Greene andFabian A. Brusok 5 7] ABSTRACT Compounds having a 2', 5-dihalo-3-tert.alkyl-5- nitrosalicylanilido nucleus useful in combattingchewing insect larvae species of the order Lepidoptera, particularlyspecies of the family Noctuidae.

5 Claims, No Drawings 2',5-DIIIALO-3-TERT.ALKYL-5- NITROSALICYLANILIDESFOR COMBATTING LEPIDOPTERA CHEWING LARVAE This invention relates to newand useful 2',5'-dihalo- 3-tert.alkyl-5-nitrosalicylanilides of thegeneral formula (OHDBH A wherein x is an integer from to l, inclusive,but preferably 0.

The compounds of this invention are high melting solids and areinsoluble in water. They are readily prepared by heating at atemperature below about 200C a. substantially equimolecular mixture of a2,5- dihaloaniline of thegeneral formula wherein A and B have theaforedescribed significance and a 3-tert.alkyl-5 nitrosalicyclic acid ofthe general formula wherein n and R have the aforedescribedsignificances, dissolved in glacial acetic acid employing 90 percentnitric acid at about room temperature. These four 3- tert.a1kylsalicylic acids are readily prepared by carboxylating a 2-tert.alkylphenol of the general formula wherein n and R have the aforedescribedsignificances with carbon dioxide in the presence of aqueous sodiumhydroxide in accordance with the Schmitt modification of the Kolbesynthesis (German patents 29,939 and 38,742) and thereafter acidifyingthe sodium salt so produced with dilute hydrochloric acid.

As illustrative of the preparation of the compounds of this inventionbut not limitative thereof is the followmg:

EXAMPLE I To a suitable reaction vessel equipped with a thermometer,agitator and reflux condenser is charged 2.4 parts by weight(substantially 0.01 mole) of 3-tert.butyl-S-nitro-salicylic acid (whichmelts with decomposition at about 225C), 1.6 parts by weight(substantially 0.01 mole) of 2,5-dichloroaniline and approximately 88.5parts by weight of monochlorobenzene. While agitating the so-chargedmass is heated to about C, whereupon 0.45 parts by weight (substantially0.0033 mole) of phosphorus trichloride in admixture with approximately12 parts by weight of monochlorobenzene is slowly added. Thereon themass is heated to the reflux temperature (about 135C) and refluxed for10 hours. Upon cooling to room temperature after standing overnight, themonochlorobenzene and other volatiles are stripped off under reducedpressure. The solid residue is first washed with dilute aqueous sodiumbicarbonate and then with water. The so-washed solid is thenrecrystallized from an ethanol-water mixture to give2',5'-dichloro-3-tert.butyl-5-nitrosalicylanilide, m.p. l-l9lC.

EXAMPLE II Employing the procedure of Example I but replacing2,5-dichloroaniline with an equimolecular amount of 2,5-dibromoanilinethere is obtained 2',5'-dibromo-3- tert.butyl-5-nitrosalicylanilide, asolid.

EXAMPLE III Employing the procedure of Example I but replacing2,5-dichloroaniline with an equimolecular amount of 2,5-difluoroanilinethere is obtained 2',5'-difluoro-3- tert.butyl-5-nitrosalicylanilide, asolid.

EXAMPLE IV Employing the procedure of Example I but replacing2,5-dichloroaniline with an equimolecular amount of 2-chloro-5-bromoaniline, there is obtained 2'-chloro-5'-bromo-3-tert.buty|-5-nitrosalicylanilide, a solid.

EXAMPLE v To a suitable reaction vessel equipped with a thermometer,agitator and reflux condenser is charged 2.8 parts by weight(substantially 0.01 1 mole) of 3-tert.butyl-6-methyl-5-nitrosalicylicacid (which melts with decomposition at about 212C), 1.8 parts by weight(substantially 0.011 mole) of 2,5-dichloroaniline and approximately 13 8parts by weight of monochlorobenzene. While agitating the so-chargedmass is heated to about 60C, whereupon approximately 0.55 parts byweight (substantially 0.004 mole) of phosphorus trichloride in admixturewith approximately 15 parts by weight of monochlorobenzene is slowlyadded. Thereon the mass is heated to the reflux temperature (about 135C)and refluxed for 10 hours. Upon cooling to room temperature afterstanding overnight, the monochlorobenzene and other volatiles arestripped off under reduced pressure. The solid residue is first washedwith dilute aqueous sodium bicarbonate and then with water. Theso-washed solid is then recrystallized from an ethanol-water mixture togive 2',5'3tert.butyl-6-methyll5-nitrosalicylanilide, m.p. 169- 170C.

EXAMPLE VI Employing the procedure of Example V but replacing2,5-dichloroaniline with an equimolecular amount of 2,5-dibromoanilinethere is obtained 2,5'-dibromo-3-tert.butyl-6-methyl-5-nitrosalicylanilide, a solid.

EXAMPLE VII Employing the procedure of Example V butreplacing2,5-dichloraniline with an equimolecular amount of 2,5-difluoroanilinethere is obtained 2',5'-difluoro-3-tert.butyl-6-methyl-5-nitrosalicylanilide, a solid.

EXAMPLE VIII Employing the procedure of Example V but replacing2,5-dichloroaniline with an equimolecular amount of2-chloro-5-fluoroaniline, there is obtained 2'-chloro--fluoro-3-tert.butyl-6-methyl-5-nitrosalicylanilide, a solid.

EXAMPLE IX To a suitable reaction vessel equipped with a thermometer,agitator and reflux condenser is charged 2.5 parts by weight(substantially 0.01 mole) of 3-tert.pentyl-5-nitro-salicylic acid, 1.6parts by weight (substantially 0.01 mole) of 2,5-dichloroaniline andapproximately 88.5 parts by weight of monochlorobenzene. While agitatingthe so-charged mass is heated to about 65C, whereupon 0.45 parts byweight (substantially 0.0033 mole) of phosphorus trichloride inadmixture with approximately 12 parts by weight of monochlorobenzene isslowly added. Thereon the mass is heated to the reflux temperature(about 135C) and refluxed for hours. Upon cooling to room temperatureafter standing overnight, the monochlorobenzene and other volatiles arestripped off under reduced pressure. The solid residue is first washedwith dilute aqueous sodium bicarbonate and then with water. The sowashedsolid is then recrystallized from an ethanolwater mixture to give solid2',5'-dichloro-3-tert.pentyl- 5-nitrosalicylanilide.

EXAMPLE X To a suitable reaction vessel equipped with a thermometer,agitator and reflux condenser is charged 2.7 parts by weight(substantially 0.01 mole) of 3-tert.pentyl-6-methyl-5-nitrosalicylicacid, 1.6 parts by weight (substantially 0.01 mole) of 2,5-dichloroaniline and approximately 88.5 parts by weight ofmonochlorobenzene. While agitating the so-charged mass is heated toabout 65C, whereupon 0.45 parts by weight (substantially 0.0033 mole) ofphosphorus trichloride in admixture with approximately 12 parts byweight of monochlorobenzene is slowly added. Thereon the mass is heatedto the reflux temperature (about 135C) and refluxed for 10 hours. Uponcooling to room temperature after standing overnight, themonochlorobenzene and other volatiles are stripped off under reducedpressure. The solid residue is first washed with dilute aqueous sodiumbicarbonate and then with water. The so-washed solid is thenrecrystallized from an ethanol-water mixture to give solid 2',5'-dichloro-3-tert.pentyl-6-methyl-5-nitrosalicylanilide.

Other 2',5-dihalo-3-tert.alkyl-5-nitrosalicylanilides of this inventionprepared as aforedescribed include 2 '-chlor0-5'-fluoro-3-tert.butyl-5-nitrosalicylanilide,

2'-fluoro-5'-bromo-3-tert.butyl-S-nitrosalicylanilide,

2'-chloro-5-bromo-3-tert.butyl-6-methyl-5-nitrosalicylanilide,

2 ',5 '-dibromo-3-tert.pentyl-S-nitrosalicylanilide,

2 ,5 '-difluoro-3-tert.pentyl-5-nitrosalicylanilide,

2 '-chl0ro-5 -bromo-3-tert.pentyl-5-nitrosalicylanilide,

2 ,5 '-dibromo-3-tert.pentyl-6-methyl-5-nitrosalicylanilide,2,5'-difluoro-3-tert.pentyl-6-methyl-5-nitrosalicylanilide, v

2 '-chloro-5 '-fluoro-3 -tert.pentyl-6-methyl-5- nitrosalicylanilide,etc.

The salicylanilide compounds of this invention are particularly usefulin combatting chewing insect larvae species of the order Lepidoptera,particularly larvae species of the family Noctuidae, and to illustratesuch but not limitative thereof is the following:

a. Cotton bollworm larvae Respective solutions of the salicylanilide tobe evaluated (itemized in Table I below) are prepared by dissolving samein sufficient acetone to provide respective concentrations of theparticular salicylanilide of 10.0 micrograms per microliter and 1.0microgram per microliter. One microliter of one of these solutions via amicroinjection apparatus is applied directly upon the dorsum of thethorax of each of 10 cotton bollworm larvae (Heliothis zea) which 10 sotreated larvae are placed immediately in a vial containing an agar baserearing medium therefor, and one microliter the other solution via amicroinjection apparatus is applied directly upon the dorsum of thethorax of each of 10 cotton bollworm larvae (Heliothis zea) which 10 sotreated larvae are placed immediately in a vial containing an agar baserearing medium therefor. Two replicates were included for eachsalicylanilide. Fortyeight hours at F after the placement in the vialmortality observations were made. The average percent mortality for eachsalicylanilide at the respective concentrations of 10.0 and 1.0micrograms per larva was found to be as follows:

TABLEI kill at a cone. in

Salicylanilide micrograms per larva of I00 1.0

2',5'-dichloro-3-tert.butyl-5-nitrosalicylanilide lOO 402',5'-dichloro-3-tert.butyl-6-mcthyl-5- nitrosalicylanilide 90 602',5'dichloro-3-tert.butyl-4'-nitro salicylanilide 50 02,5-dichloro-3-tert.butyl-6-methyl-4'- nitrosalicylanilide 60 02',5-dichloro-3-isopropyl-4-nitrnsalicylanilide v 20 02',4,5-trichloro-3-tert.butyl-salicylanilide 0 0 U.S. 3,388,163

b. Southern armyworm larvae Respective solutions of the salicylanilideto be evaluated (itemized in Table II below) are prepared by dissolvingsame in sufficient acetone to provide respective concentrations of theparticular salicylanilide of 1.0 and 0.1 micrograin per microliter. Onemicroliter of one of these solutions via a microinjection apparatus isapplied directly to each of lima bean leaf discs 0.25

inch in diameter, and one microliter of one of the other solutions via amicroinjection apparatus is applied directly to each of 10 lima beanleaf discs 0.25 inch in diameter. Thereafter individual second instarsouthern armyworm larvae (Pradenia eridania) are placed beside each leafdisc and the disc and larva encaged with a plastic cap 0.875 inch indiameter. Two replicates were included for each salicylanilide.Fortyeight hours of room temperature after the encagement mortalityobservations were made. The average percent mortality for eachsalicylanilide at the respective concentrations of 1.0 and 0.1 microgramper larva was found to be as follows:

TABLE II kill at a cone. in

salicylanilide mierogram per larva ofl.0 0.1

2',5'-dichloro 3-tert.butyl-6-methyl-5- nitrosalicylanilide 90 302',S-dichlore-3-tert.butyl-6-methyl-5'- nitrosalicylanilide 30 03',5-dichloro-3-tert.butyl-6-methyl-4'- nitrosalicylanilide 30 04',5-dichloro-3-tert.butyl-6-methyl-3'- nitrosalicylanilide i 0 O2',5'-dichloro-3-tert.butyl-S-nitrosalicylanilide I00 702,5-dichloro-3-tert.butyl-S'-nitrosalicylanilide 7O 04',5-dinitro-3-tert.butyl-2'-chlorosalicylanilide 60 03,4-dichloro-3-phenyl-5mine-salicylanilide i U 0 o4,S-dichloro-3-tert.butyl-2'-nitrosalicylanilide O 04',5-dichloro-3tert.butyl-3-nitro-salicylanilide 40 07.,5,5'-trichloro-3 tert.butyl-4" nitrosalicylanilide 0 03',s-dichloro-3-tert.butyl-4'-nitrosalicylanilide 70 02',5-dichloro-4'-nitrosalicylanilide 0 02',5-dichloro-3-methyl-4-nitro-salicylanilide 0 02',5-dichloro-3-ethyl-4'-nitro-salicylanilide 0 02',S-dichloro-3-isopropyl-4'-nitrosalicylanilide 0 03',5-dichloro-3-phenyl-4'-nitro-salicylanilide O t i I 02',3,5-trichloro-4'-nitrosalicylanilide 0 02',5-dichloro-S'-nitrosalicylanilide 0 02,5-dichloro-3-(4-chlorophenyl)-5'- nitroaalicylanilide 60 03',4',5-trichloro-3mitrosalicyI-anilide 0 0 described and thepreparation thereof either specifically, generically or analogously fromthe appropriate substituted salicylic acid and the appropriatesubstituted aniline in the presence of phosphorus trichloride in U.S.3,079,297 and U.S. 3,388,l63.

"" m.p. 250253C prepared by heating at about 220230C an intimateequimolecular mixture of 3,4-dichloroaniline and phenyl S-nitro-B-phenylsalicylate (m.p. l42.5-l43.5BC).

Although the salicylanilides of this invention are useful per se indestroying Lepidoptera larvae, it is preferable that they be supplied tothe larvae or to the environment of the larvae in a dispersed form in asuitable extending agent. The exact concentration of the salicylanilidesof this invention employed in destroying said larvae can varyconsiderably provided the required dosage (i.e. toxic or larvicidalamount) thereof is supplied to the larvae or to the environment of thelarvae. When the extending agent is a liquid or mixture of liquids (i.e.as in solutions, suspensions, emulsions, or aerosols) the concentrationof the salicylanilide employed to supply the desired dosage generallywill be in the range of 0.001 to 50 percent by weight. When theextending agent is a semi-solid or solid, the concentration of thesalicylanilide employed to supply the desired dosage generally will bein the range of 0.1 to 25 percent by weight. From a practical point ofview, the manufacturer must supply the user with a low cost concentrateor spray base or particulate solid base in such form that, by merelymixing with water or finely divided inert solid extender (e.g. powderedclay or talc) or other low cost material available to the user at thepoint of use, he will have an easily prepared larvicidal spray orparticulate solid. In such a concentrate composition, the salicylanilidegenerally will be present in a concentration of 5 to 95 percent byweight, the residue being any one or more of the well known pesticidaladjuvants, such as the surface-active clays, solvents, diluents, carriermedia, adhesives, spreading agents, humectants, and the like, butparticularly a finely divided solid extender.

There are a large number of organic liquids which can be used for thepreparation of solutions, suspensions or emulsions ofthe salicylanilidesof this invention. For example, isopropyl ether, acetone, methyl ethylketone octanone, dioxane, cyclohexanone, carbon tetrachloride, ethylenedichloride,

tetrachloroethane, hexane, heptane and like higher liquid alkanes,hydrogenated naphthalenes, solvent naphtha, benzene, toluene, xylene,petroleum fractions (e.g. those boiling almost entirely under 400F, andhaving a flash point above about F, particularly kerosene), mineral oilshaving an unsulfonatable residue above about 80 percent and preferablyabove about percent. In those instances wherein there may be concernabout the phytotoxicity of the organic liquid extending agent a portionof same can be replaced by such low molecular weight aliphatichydrocarbons as dipentene, diisobutylene, propylene trimer, and the likeor suitable polar organic liquids such as the aliphatic ethers and thealiphatic ketones containing not more than about 10 carbon atoms asexemplified by acetone, methyl ethyl ketone, diisobutyl ketone, dioxane,isopropyl ether, and the like. In certain instances, it is advantageousto employ a mixture of organic liquids as the extending agent, e.g. anaromatic hydrocarbon and an aliphatic ketone.

Whenthe salicylanilides of this invention are to be supplied to thelarvae or to the environment of the larvae as aerosols, it is convenientto dissolve them in a suitable solvent and disperse the resultingsolution in dichlorodifluoromethene or like chlorofluoroalkane whichboils below room temperature at atmospheric pressure.

The salicylanilides of this invention are preferably supplied to thelarvae or to the environment of the larvae in the form of emulsions orsuspensions. Emulsions or suspensions are prepared by dispersing thesalicylanilides of this invention either per se or in the form of anorganic solution thereof in water with the aid of a water-solublenon-ionic or anionic surfactant or mixtures thereof. The term surfactantas employed here and in the appended claims is used as in Volume 11 ofSchwartz, Perry and Berchs Surface Active Agents and Detergents (1958,lnterscience Publishers, Inc., New York) in place of the expressionemulsifying agent", to connote generically the various emulsifyingagents", dispersing agents", wetting agents and spreading agents" thatare adapted to be admixed with the active compounds of this invention inorder to secure better wetting and spreading of the active ingredientsin the water vehicle or carrier in which they are insoluble throughlowering the surface tension of the water (see also Frear Chemistry ofInsecticides, Fungicides and Herbicides", second edition, page 280). Thesurfactants contemplated are the wellknown capillary active substanceswhich are non-ionic or anionic and which are described in detail inVolumes land 11 of Schwartz, Perry and Berchs Surface Active Agents andDetergents", (1958, lnterscience Publishers, Inc., New York) and also inthe November 1947 issue of Chemical Industries (pages 811-824) in anarticle entitled Synthetic Detergents by John W. McCutcheon and also inthe July, August, September and October, 1952 issues of Soap andSanitary Chemicals under the title Synthetic Detergents". Thedisclosures of these articles with respect to non-ionizing capillaryactive substances are incorporated in this specification by reference inorder to avoid unnecessary enlargement of this specification. Thepreferred surfactants are the water soluble anionic and non-ionicsurface active agents set forth in US. Pat. No. 2,846,398 (issued Aug.5,1958).

The salicylanilides of this invention can be dispersed by suitablemethods (e.g. tumbling or grinding) in solid extending agents either oforganic or inorganic nature and supplied to the larvae environment inparticulate form. Such solid materials include for example, tricalciumphosphate, calcium carbonate, kaolin, bole, kieselguhr, talc, bentonite,fullers earth, pyrophillite, diactomaceous earth, calcined magnesia,volcanic ash, sulfur and the like inorganic solid materials, and includefor example, such materials of organic nature as powdered cork, powderedwood, and powdered walnut shells. The preferred solid carriers are theadsorbent clays, e.g. bentonite. These mixtures can be used forlarvicidal purposes in the dry form, or by addition of water-solubleanionic or non-ionic surfactants the dry particulate solids can berendered wettable by water so as to obtain stable aqueous dispersions orsuspensions suitable for use as sprays.

For special purposes the salicylanilides of this invention can bedispersed in a semi-solid extending agent such as petrolatum with orwithout the aid of solubility promoters and/or surfactants.

In all of the forms described above the dispersions can be providedready for use in combatting the larvae or they can be provided in aconcentrated form suitable for mixing with or dispersing in otherextending agents. As illustrative of a particularly useful concentrateis an intimate mixture of a salicylanilide of this invention with awater-soluble anionic or non-ionic surfactant or mixtures thereof whichlowers the surface tension of water in the weight proportions of 0.1 to15 parts of surfactant with sufficient of the salicylanilide of thisinvention to make parts by weight. Such a concentrate is particularlyadapted to be made into a spray for combatting various forms ofLepidoptera larvae by the addition of water thereto. As illustrative ofsuch a concentrate is an intimate mixture of 20 parts by weight of2,53-tert.butyl-5-nitrosalicylanilide and 2 to 4 parts by weight of awater-soluble non-ionic surfactant such as the polyoxyethylenederivatives of C,, alkyl substituted phenols such as nonylphenol ordodecylphenol.

Another useful concentrate adapted to be made into a spray forcombatting Lepidoptera larvae is a solution (preferably as concentratedas possible) of a salicylanilide of this invention in an organic solventtherefor. The said liquid concentrate preferably contains dissolvedtherein a minor amount (e.g. 0.5 to 10 percent by weight of the weightof the new larvicidal agent) of a non-ionic or anionic surfactant, whichsurfactant is also water-soluble. As illustrative of such a concentrateis a solution of 2',5'-dichloro-3-tert.buty-6-methyl-5-nitrosalicylanilide in a mixture of xylene and 2-octanone which solutioncontains dissolved therein a water-soluble non-ionic surfactant such asthe polyoxyethylene derivatives of C alkyl substituted phenols such asnonylphenol and dodecylphenol.

In all of the various dispersions described hereinbefore for larvicidalpurposes, the active ingredient can be one or more of thesalicylanilides of this invention. The salicylanilides of this inventioncan also be advantageously employed in combination with otherpesticides, including, for example, nematocides, bactericides,fungicides, and herbicides. 1n this manner it is possible to obtainmixtures which are effective against a wide variety of pests and otherforms of noxious life.

In the destruction of Lepidoptera larvae the salicylanilides of thisinvention either per se or compositions comprising same are supplied tothe larvae or to their environment in a toxic or larvicidal amount. Thiscan be done by dispersing the new Lepidoptera larvicidal agent orlarvicidal composition comprising same in, on or over an infestedenvironment or in, on or over an environment the larvae frequent, e.g.agricultural soil or other growth media or other media attractable tothe larvae for habitational or sustenance purposes, in any conventionalfashion which permits the larvae to be subject to the larvicidal actionof the salicylanilides of this invention. Such dispersing can be broughtabout by applying sprays or particulate solid compositions to a surfaceinfested with the larvae or attractable to the larvae, as for example,the surface of an agricultural soil or other habitat media such as theabove ground surface of host plants by any of the conventional methods,e.g. power dusters, boom and hand sprayers, and spray dusters. Also forsub-surface application such dispersing can be carried out by simplymixing the new larvicidal agent per se or larvicidal spray orparticulate solid compositions comprising 2. The method of combattingchewing insect larvae same with the infested environment or with theenspecies of the order Lepidoptera which comprises apvironment thelarvae frequent, or by employingaliquid plying to the above groundsurface of host plants carrier for the new larvicidal agent toaccomplish subthereof a larvicidal amount of a 2',5'-dichloro-3- surfacepenetration and impregnation therein. tert.butyl-S-nitrosalicylanilideof the formula.

What is claimed is 1. The method of combatting chewing insect larvae(CHQMH o 1 species of the order Lepidoptera which comprises ap- NO?plying to the above ground surface of host' plants thereof a larvicidalamount of a 2',5'-dihalo-3-tert.bu- OH 1 tyl- S-nitrosalicylanilide ofthe formula 3) a it have a (CH3):

U wherein n IS an integer from 0 to 1, inclusive. 7 l5 3. The method ofclaim 2 wherein n is O and th i OH B chewing insect larvae species is ofthe family Noctuidae. xCHm 4. The method of claim 3 wherein the chewinginsect larvae species is Heliothis zea.

' wherein n an integer from to 1, inclusive, wherein 5. The method ofclaim 3 wherein the chewing insect A and B respectively are halogen ofatomic weight in larvae Species is Pmdenia therange of 18 to 80. A s:

2. The method of combatting chewing insect larvae species of the orderLepidoptera which comprises applying to the above ground surface of hostplants thereof a larvicidal amount of a2'',5''-dichloro-3-tert.butyl-5-nitrosalicylanilide of the formula.wherein n is an integer from 0 to 1, inclusive.
 3. The method of claim 2wherein n is 0 and the chewing insect larvae species is of the familyNoctuidae.
 4. The method of claim 3 wherein the chewing insect larvaespecies is Heliothis zea.
 5. The method of claim 3 wherein the chewinginsect larvae species is Prodenia eridania. 80.